Tank Combat in Spain: Armored Warfare During the Spanish Civil War 1936–1939

By Anthony J. Candil

“Recounts in considerable detail how Germany, Italy, and Soviet Russia intervened in Spain, supplying troops and equipment to the warring sides.” —ARMOR Magazine
 
Although Spain had been for many years on the periphery of the great affairs of Europe, within a few months of the Civil War breaking out in 1936, three out of the four major European powers—Italy, Germany, and the Soviet Union—decided to intervene. Spain turned out to be the perfect proving ground to carry out controlled, realistic experiments with live weapons and troops. This book covers the theories of the three main contributors that provided armor to the warring parties in the civil war, how those contributions shaped combat, and how the lessons learned were then applied to tank combat in World War II.
 
The use of tanks in the Spanish Civil War wedded traditional war to modern technology. The fighting in Spain did not offer any easy answers, however, to the question of infantry-armor cooperation, primarily because the tanks supplied were not very worthy and had been supplied in small numbers, even though the Republicans organized an “armored division.” The situation for the tanks on the Nationalist side was so bad in practical terms that they reused captured Russian armor in their units. Tank employment in Spain did offer many lessons, but the lessons did not always lie in what was done or accomplished but precisely on what was not done and was not accomplished.
 
“Offers important insight into the employment of tanks during the war, lessons learned (or not learned) by the participating armed forces.” —Globe at War

• Language: English
• Publisher: Casemate Publishers
• Release date: May 3, 2021
• ISBN: 9781612009711

Book preview

Preface

As a senior Armor officer in the Spanish Army, I had direct experience of the struggle of the tank concept in Spain, not only to replace the horse, but to establish it as the primary combat arm in mobile warfare and to create an armored branch within the Spanish land forces, as in most Western armies; however, it was to no avail.

Nevertheless, I was fortunate in being intimately involved in armored warfare and the improvement of Spanish armor since I joined the Spanish Army, almost from the beginning and my early days at the military academy. Since then I have been both directly and indirectly concerned with all kind of developments in tanks and armored warfare, until I voluntarily ended my military career in Spain and relocated to the United States in 2007.

As a theoretical practician of the art of warfare—or business, whatever we may call it—I have always been interested in theory, and in the relation between theory and practice. My classical education with the Jesuits, combined with a naturally argumentative personality, had always led me to question generally accepted, established responses, methods, or systems. Certainly, without war experience it has been difficult to support my rationale, but my learning and experience gained alongside the U.S. Army—as a graduate of the U.S. Armor Officers Advanced Course—and the British, French, Israeli, Italian, and German armies, led me to question a great deal of what I had been taught or told in Spain. Indeed, one of the most important lessons I learnt was to distrust almost everything I was told and to test its validity by relentless probing.

At the end of my military career I spent several frustrating years linked to armor procurement, concerned with the design and development of the Spanish version of the Leopard 2, the main battle tank for the Spanish Army, and other related vehicles. This led me to initiate a thorough re-examination of all the factors which affected their design, during the course of which I came to the conclusion that many views, decisions, or opinions were based on very flimsy evidence indeed, and as proven later, had come to be reviewed—certainly not in Spain, but in Germany and even the United States—as a consequence of the asymmetric fighting taking place in new theaters of operations.

When I began to study and write about the history of tank employment in the Spanish Civil War, having access to new accounts written by various authors, I was struck by the differences between what I learned and the generally accepted view that developed immediately following the conflict and soon crystallized into a myth which, until now, has been hard to dislodge from people’s minds.

I have long been interested in clarifying how much success, or failure, can be related to the official history or the unofficial influence that came from it. Clarity of thought, allied to imagination and the willingness, if not the propensity, to discard unfruitful traditional methods—aided by an always ready pen or outspoken attitude—combined with my knowledge of the history of warfare, have been useful tools in achieving results in my work.

The army that developed in Spain following the Civil War failed to understand what tanks could do, if properly used, and as a consequence no armor branch of any sort was created, with tanks merely subordinated to support the infantry. Luckily for Spain, the need to demonstrate how wrong this policy was never came to light.

For a long time, the Spanish Civil War has been portrayed as a romantic episode of the 20th century where defenders of freedom and democracy were confronted by the evil forces of totalitarianism and dictatorship, appearing as such in some of Ernest Hemingway’s books and in various Hollywood movies. The reality was quite different, with neither side being quite as they were portrayed. The truth was that behind the flag of democracy and freedom rallied a mixture of romantic and idealistic people, who were mostly ignorant of the covert Communist attempt to seize power in Spain; while on the Nationalist side, most of the conservative forces of the nation were prey to Fascist and Nazi ideologies. In the end, the Spanish Civil War came to be a clash between Soviet Communism and Nazi/Fascist-inspired ideologies, resulting in over half a million deaths and the complete destruction of a country.

Historians of armored warfare have often misinterpreted the role of armor in the Spanish Civil War. Some have stated that the conflict was merely a laboratory to test modern armored tactics, while others concluded that there were few if any lessons to be learned. The confusion of historians is understandable, as the conflict was not a demonstration of brilliant tactics and great battles, but rather a series of battles of attrition.

At no point during the conflict did either side possess enough armor to execute the tactically independent operations envisioned by some of the interwar armor theorists. Nevertheless, tank forces proved useful once effective tactics were developed. Moreover, lessons were learnt by all the warring parties and both sides quickly found that the type of tanks employed were not always ideally suited for the missions they performed, which probably led their leaders to make the wrong assessments.

The Spanish Civil War has been described frequently—but inaccurately—as a contest between democracy and fascism. While it is true that Italian Fascism supported the Nationalist side, there was no real democracy on the Republican side. The uprising was designed, at first, as an exclusive military affair to remove the radical left from power and convert the existing regime into a conservative republic, in which democracy—as we understand it today—would have been severely curtailed. The military was divided, as was Spanish society. However, instead of a successful coup d’état, the so-called Nationalists ended up in control of only half the country’s army, less than a third of the air corps and the navy, and about a third of the country’s resources. Without the full weight of the military or the country behind the Nationalists, a civil war broke out in which the military rebellion would have soon been defeated had its leaders not been able to lobby Italy and Germany for military aid.

To understand the role that tanks were to play in the conflict, one must first develop a basis for understanding what the war was truly about. The Spanish Civil War was not only a clash between two systems, two societies, and multiple ideologies, but a host of other systems as well. On the battlefield, different doctrines, training, and military intelligence affected the outcome of battles as much as weapons and manpower. The Nationalists managed to maintain the all-important systems of national mobilization, logistics, finance, and—to a certain extent—research and development. Ultimately, the Republican side was engulfed in chaos, both from a societal and military perspective.

In the end, the war was a clear-cut revolutionary/counterrevolutionary contest between left and right, with the fascist totalitarian powers supporting the right and the Soviet totalitarian power backing the left. It was not, as many historians have perpetuated, a precursor to World War II, which began only when a pan-totalitarian coalition was formed through the Nazi-Soviet Pact, with the aim of allowing the Soviet Union to conquer a sizable swath of Eastern Europe while Germany was left free to conquer much of the rest of the continent. Spain, on the other hand, led then by General Franco—who was the unquestionable victor of the Spanish war—never officially entered World War II.¹

The Republicans, also called Reds, were fighting against conservative society, the power of the Church, the landlords, the military, and anybody who was considered as being wealthy and privileged. The Rebels, nicknamed Nationalists, under General Francisco Franco, targeted their revolution against Marxism, anarchism, disorder, dictatorial trade unions, atheism, and in general against anybody not respecting the ideas of God, Motherland, and King; but ultimately, they became easy prey for totalitarianism.

For both sides, the struggle was a kind of holy war. The Nationalists even managed to convince Pope Pius XI to declare the war as a crusade against Bolshevism, but the cruel truth was that it gave way to Nazism and Fascism, the concentration camps, and World War II. During the Spanish Civil War, new tactics were tested, including terrifying Stuka air attacks, bombing of defenseless cities, and an almost total war against civilians. Stalin, Hitler, and Mussolini were the main actors behind the scenes; however, Spaniards were just trying to establish their identity and future. Even if, at the beginning, most intellectuals and artists supported the Republic, later most withdrew their support due to the rising influence of the Communist Party and the terror campaigns conducted in Republican Spain against Catholics, monarchists, and even ordinary conservative people.

When the war started in 1936, the so-called Nationalists and their supporters represented authority, the interest of free-economy, and centralized government, as opposed to a regional decentralized autonomy. On the other hand, the Republicans formed an incompatible alliance between authoritarian communists and libertarian anarchists. Spain, at that time, had little industry and an agricultural system with more than four million workers, kept at the limits of human endurance and sacrifice. Corruption, financial scandals, and speculations in public office often made the headlines, together with a tax system that was little more than a farce.

Just as the revolutionary Spanish Republic was "sui generis" politically speaking, the war was uniquely military, as Professor Stanley Payne very cleverly points out. It was typical neither of World War I nor of World War II, but rather represented a kind of transition war halfway between the two and displayed certain traits of each. Most of the weaponry used was more typical of World War I, though occasionally the employment of armor and aircraft was more characteristic of World War II.

The Spanish Civil War was an event of interest to the Military Intelligence Division (MID) of the U.S. War Department.² Through the Army attachés stationed in the major embassies in Europe, the MID received technical and tactical information concerning weapons used in Spain by the Germans, Soviets, and Italians. Although the information gathered by the attachés was often random and incomplete, they—and their sources—saw trends in the development and use of modern weapons, especially the tank and antitank guns. The efforts of the attachés provided the MID with information that could be analyzed, and from which it could draw conclusions about the nature of a future European war. That the United States Army could not or would not make use of the lessons of the war in Spain was not due to a lack of information.

To many, the Spanish Civil War proved inconclusive regarding mechanized warfare. Despite attempts by Soviet, German, and Italian advisers to use newly devised mechanized theories, the lack of quality of both crews and the tanks employed, as well as the insufficient number of tanks used in operations, provided wrong impressions on the usefulness of armored forces.

As for lessons from the war, even if they were amply attested, it was not of much value to draw too detailed deductions of general application from individual episodes. Nevertheless, many tended to support the view that the ultimate effect of mechanization could be to enhance the power of defense rather than revive that of the offensive, while the Germans proved the opposite to be the case in the earlier stages of World War II.

CHAPTER 1

Overview of Military Operations

July 18, 1936–April 1, 1939

It is difficult to understand tank combat in the Spanish Civil War without an overall military grasp of the conflict. For almost three years, Spain was tainted in blood. Conflict in a country that was neither a major player in European politics nor a cornerstone in the struggle for supremacy in Europe, ultimately led, even if unwillingly, to the major global disaster that was World War II.

To start with, we must bear in mind that the military rebellion was not initially a success, which was why the war began, as not all the armed forces joined the military uprising against the Republican government. Indeed, from a total of more than 80 generals on active duty in July 1936, fewer than 30 joined the uprising. A great number of those who joined were summarily executed at the outbreak of the war by both sides.

For the purposes of this study and a quick understanding of the conflict, we can establish four main stages in the development of the war:

•Stage one : from July 1936 until November 1936, when the Nationalist forces, outnumbered but superior in combat procedures, managed to consolidate their capacities and reached Madrid, circling the city from the west and the south, but failed to take over the capital.

•Stage two : from mid-November 1936 until late October 1937, when supplies and aid received by both sides managed to establish some balance of power, although the conquest of the Basque Country by the Nationalists gave them a substantial superiority.

•Stage three : from late October 1937 to mid-November 1938, when the Republican side was clearly on the defensive and conducted mainly delaying operations. Among them, the battle of attrition at el Ebro —the longest battle of the war—is the main example.

•Stage four : from mid-November 1938 until the end of March 1939, when the Republican side collapsed completely and stopped all resistance, with General Franco announcing the end of the war on April 1, 1939.

Stage one

In the beginning, the Nationalist side faced numerous unknown situations as their local commanders actively tried to consolidate their positions all over the area they seized control of, fighting off the Republican forces. There was little coordination, which ultimately led to the establishing of a unified command on October 1, 1936, which was entrusted to General Franco.

In spite of the Nationalist numerical inferiority, following orders from General Emilio Mola—the military commandant at Pamplona, and the effective head of the uprising in the north—a mobile column¹ began moving from Pamplona towards Madrid, threatening the capital and the government, forcing the Republican leaders onto the defensive. From Pamplona, the Nationalists also managed to take Irun and San Sebastian at the same time, cutting all links between the Basque Country and France by mid-September 1936.

However, it became obvious that these forces would be incapable of achieving any important objectives, and much less obtain any decisive victory. Reinforcements were key for the uprising, and these could only come from the Army of Africa, which comprised the best troops Spain then had, deployed in the Spanish Protectorate of Morocco.

By the end of July 1936, the Nationalist forces were in dire straits. The Republic held two-thirds of the country, including the capital and major urban centers, along with the gold reserves and most of the industry. The Republic also controlled most of the Spanish Navy,² and from July 19, Republican warships started patrolling the waters between Morocco and the Spanish mainland.

Even though Franco managed to land two battalions of colonial troops in southern Spain and some minor units were airlifted to Seville, it was clear that without substantial air and naval transportation, along with air support capability, not much would be achieved. Therefore, General Franco sent emissaries to Berlin and Rome, requesting transport aircraft in order to carry on the airlift of his troops. Germany sent 20 Junkers Ju-52 transport aircraft, and Italy 12 Savoia SM-81 transport/bombers, plus some fighter aircraft. As a result of their help, between July 29 and August 5, the Nationalists managed to fly 1,500 men of the Army of Africa across the Straits of Gibraltar, thereby establishing the first military airlift³ in history.

On August 5, Franco challenged the Republican naval blockade with a convoy of merchant ships, carrying some 3,000 soldiers, equipment, and heavy weapons, then about 15,000 more men were moved between August 5 and August 15. This achievement, a clear military success, was a major psychological blow for the Republican government, for even though the Republican Navy continued to deploy around the Straits, it was no longer a threat to the Nationalists.

From August 6, cargo ships regularly crossed the Straits of Gibraltar, under the cover of Italian bombers. By the end of September, the Republicans had completely lost control of the Straits of Gibraltar, with the Nationalists enjoying free passage between Spanish Morocco and the mainland until the end of the war. This was a major success for the Nationalist rebels and a huge setback for the Republic.

After landing in Spain, the forces of the Army of Africa advanced north, capturing Badajoz near the border with southern Portugal and linking with other Nationalist forces at Cáceres. Making remarkably rapid gains—and closing all land communications of the Republic with Portugal—they then turned north-eastwards towards Madrid and liberated Toledo, where the Infantry School (the Alcazar) had been under siege by Republican militias since the early days of the uprising. Another small force spread throughout Andalusia, took control of key locations, and reinforced the cities of Granada and Cordoba.

Due to the Army of Africa’s advance, almost all western Spain was in Nationalist hands by the end of September 1936, and Franco reached the outskirts of Madrid late in October, forcing the government to flee to Valencia, on the eastern coast. That was a considerable psychological blow to the Republic, badly hitting the morale of its supporters.

Without doubt, the most important military development of this first stage of the war was the effective campaign of the Army of Africa, with its surprise airlift and impeccable crossing of the Straits of Gibraltar, and immediate advance towards Madrid, breaking all effective links between the Republic and Portugal, as well as isolating the Basque Country in the north once the Nationalists closed the border with France. Overall, it was a great leap forward for the Nationalist forces. To paraphrase a later quote from Churchill, it could be said that perhaps it wasn’t the beginning of the end, but it was the end of the beginning. However, there was still a long and arduous journey ahead. It was only at the end of this stage of the conflict that serious employment of tanks began.

A key fact at the time was the Republican government’s inability to crush the military rebellion, failing not only to anticipate the rebels’ intentions, but to react with initiative and bold determination. Allowing the Nationalists to cross, practically unopposed, the Straits of Gibraltar was a grave mistake, that in the end they would pay for dearly. Failing to confront Franco’s columns on their advance to Madrid until they almost reached the southern suburbs of the capital, while trying to block the wrong avenue of approach from Cordoba, was also a monumental error. The government’s inability to mobilize its troops and establish an effective military force to confront the rebels until it was too late had already sealed the fate of the Republic.

Stage two

From mid-November 1936 onwards, the war began to rage, becoming more complex and even reaching an almost international dimension. There were several great battles throughout 1937, a year when both sides consolidated their positions and the Spanish Civil War became not only a Spanish affair. It was also the year when, within the Republican government, some leaders⁴ realized that they could not win the war, mainly due to the fact that the entire northern part of country—the Basque provinces and Asturias—fell into Nationalist hands, thus depriving the Republic of its main industrial base and logistical support, apart from considerable materiel losses in armament, equipment, and personnel.

Quoting once more Stanley Payne,⁵ the Spanish Civil War was without a doubt a low-intensity conflict, but full of high-intensity battles. In the Central front, around Madrid, the main clashes during this period were the battle of Jarama in February 1937, the battle of Guadalajara in March 1937 and the battle of Brunete in July 1937. None of these battles were decisive and none allowed the Nationalists to capture Madrid, but all severely weakened the Republican forces and drained their manpower. Tanks were also widely employed in all these battles.

During the first of these battles—fought between February 6 and February 27—Franco tried to cross the Jarama River to cut off the road between Madrid and Valencia, where the Republicans had relocated their government. The battle’s results were inconclusive: Franco’s troops managed to get onto the east bank of the Jarama River, but failed to sever communications between Madrid and Valencia. However, the Nationalists did put parts of the main road between the two cities under machine-gun and rifle fire. By the end of February, the front lines had stabilized, with both sides consolidating and fortifying their positions to the point where no useful assault could be undertaken. Nationalists and Republicans alike had suffered very heavy casualties, and their troops were exhausted and low on ammunition and food. The battle was well described by Hemingway, and perpetuated in many songs of the time, including some performed later by folk singers such as Woody Guthrie and Pete Seeger in the United States.

Although the Nationalists succeeded in crossing the Jarama River and resisted all efforts to dislodge them from their footholds, the Madrid– Valencia road remained out of reach and firmly in Republican hands. Consequently, the area lost much of its strategic importance and merged into the wider front.

The battle of Guadalajara was an operation that, even if well conceived and planned, was executed only after some misplaced Italian optimism due to the relatively easy walkover of the Italian volunteers in the capture of Malaga early in February 1937. Following the battle of Jarama, the Nationalists were incapable of any major efforts in the Central front, and Guadalajara became an almost exclusive Italian affair. The goal of the Italian High Command was to take the cities of Guadalajara and Alcala, the latter only 20 miles from Madrid. They hoped the Republican forces would crumble, Madrid would be occupied, and a quick surrender would follow, thus bringing an end to the war. However, matters did not turn out that way.

The most important strategic consequence of the Italians losing the battle was the abandonment of the Nationalist goal of conquering Madrid, the capital thus remaining in Republican hands until the end of the war on April 1, 1939. Italian morale was devastated and Mussolini was furious, as the battle became the most publicized Republican victory of the entire war. The battle soon became a propaganda trophy, but it was not a turning point. On the contrary, it helped the Nationalists adopt a long-term indirect strategy, firstly by reducing any vulnerable Republican positions they could find.

The summer of 1937 witnessed one of the bloodiest clashes of the Spanish Civil War, the battle of Brunete, from July 6 until July 25. It proved an unsuccessful attempt by the Republicans to alleviate the pressure exerted by the Nationalists in the north, especially against Santander and on the Madrid front. Although initially successful, the Republicans were forced to retreat from Brunete and in the end suffered devastating casualties. From a political standpoint, the offensive at Brunete was chosen to satisfy Communist demands, to prove to the Russians that the Spanish leadership possessed military initiative. Russian advisors had been pressing for an attack on Brunete since the early spring of 1937, but in the end the Communists suffered a major loss of prestige as the offensive failed to prevent Nationalist troops from completing the encirclement of Madrid from the north.

After Brunete, with the occupation of the north by Franco’s forces almost completed, the war effort focused on northeastern of Spain, largely due to a Republican decision driven once more by political considerations rather than military procedures. Following the failure of their offensive at Brunete, the Republicans admitted that nothing of importance could be achieved by major operations in the Central front. The Republican government soon moved again, this time from Valencia to Barcelona, and thus the war’s operational goals changed once more.

Elsewhere, the Nationalists had secured clear victories. Early in the year—from mid-January to mid-February 1937—the capture of the coastal city of Málaga, on the southern Mediterranean coast, contributed to further complicating the logistics of the Republicans, confining the Republican Navy to operating only in the eastern littoral, and even then, under permanent threat of attack from aircraft operating from Nationalist bases in the Balearic Islands. Only a handful of Italian tanks were employed in these actions by the Nationalists.

In the north, starting in April 1937, the Nationalist forces under the leadership of General Mola⁶ initiated an all-out offensive against the province of Biscay, finally entering Bilbao on June 19 and kicking out the Republicans beyond the province of Santander. The intended offensive against Santander was delayed by the Republican offensive in Brunete, but it finally commenced on August 14, and by September 1, Santander had been captured. Immediately after, the Nationalist forces entered Asturias, liberating Oviedo—which had been under siege since the early days of the uprising in 1936—and the harbor of Gijon, ending the whole campaign on October 24. The entire northern region of Spain, from Galicia to the French border, was then under Nationalist control.

The only overland channel of communication left between the Republic and France was through Catalonia. The Republic had lost a key region, along with about 200,000 troops plus a huge amount of military equipment. It was a disaster with serious strategic consequences: without doubt, this was the beginning of the end.

By this time, both sides had received considerable aid from abroad, so their armies bore little resemblance to those when the war began in July 1936. Italy was the country that diverted the most resources in helping the Nationalists, contributing not only equipment and armament, but a large number of troops. Italian submarines began to attack all Spanish, Soviet and other nations’ merchant ships that were transporting materiel and supplies for the Republic through the Mediterranean,⁷ making it very difficult for supplies from the Soviet Union to reach the Republic. There was also German involvement, including contributions from the Kriegsmarine, besides the technical and military aid that had been sent to General Franco since the beginning of the war.

The Nationalists’ attempt to capture Madrid had some serious tactical drawbacks. First and foremost, General Franco’s troops were outnumbered by more than two to one by the defenders, and although the Nationalists were far better trained and equipped, another disadvantage was their inability to surround Madrid and cut if off completely from outside help as the road to Valencia always remained open.

Following the first battle for Madrid, the Republican government tried to reorganize its armed forces from a collection of people’s militias into a regular army, the so called "Ejército Popular" or Popular Army mirrored on the Soviet Red Army. This was achieved by integrating the militias into the structure of elements of the pre-war army which had sided with the Republic. While in theory reducing the power of political parties in relation to the government, in practical terms it increased the influence of the Communist Party, which was the main source of Soviet arms and foreign volunteers and advisors.

A new limited offensive commenced on August 24, aiming to break into the Nationalist rearguard and disrupt their final battles in the north. The Republican objective was the town of Zaragoza, on the banks of the Ebro River, but they failed and only managed to capture the ruins of Belchite, a small town in the middle of Aragon of no tactical or strategic value. For the Republicans, Zaragoza was more than a symbolic target; it was the communications hub of the entire front in Aragon. The whole operation lasted just 13 days, and once again the Republicans suffered a considerable loss of badly needed armament, equipment, and personnel.

Stage three

By early September 1937, the Aragon front was stabilized at an average of 20 miles from Zaragoza, and the Republicans and Nationalists both took a brief break. The Nationalists intended to take advantage of their occupation of the northern zone, while the Republicans were hoping that, given time, the international situation would help their situation. By the end of the year, both sides had completed their reorganization and mobilization reached its highest, each having about 700,000 personnel in their field armies.⁸ However, the quality, discipline, and morale of troops was clearly superior on the Nationalist side.⁹

The Nationalist High Command thus decided to mount an offensive on the Madrid front by the end of the year, again in the Guadalajara sector, but slow preparations and accumulation of troops and supplies, combined with good Republican intelligence, gave away the operation. The Republicans therefore decided to launch an offensive-defensive battle to disrupt the Nationalist plan, aiming for limited destruction of forces and obtaining some advantage for further exploitation. The area chosen was the weakest point of the whole Nationalist front, near the town of Teruel in southern Aragon. The Republicans deployed some 40,000 men, with the armored force, inefficiently, split up among the attacking units. The Nationalist forces consisted mainly of the 52nd Infantry Division, with less than 10,000 men; consequently, the Republicans initially managed to obtain some local success.

The Republican attack began on December 15, just three days before the intended Nationalist offensive in the Guadalajara sector; by December 19, the Republicans had reached the outskirts of Teruel, and on December 25, they proclaimed victory. However, the city didn’t surrender until January 7, 1938. Franco’s headquarters were taken aback upon hearing of the offensive, and against all advice, and at the cost of canceling the prepared offensive against Madrid via Guadalajara, Franco decided to re-establish the front and recapture Teruel. Uppermost in Franco’s mind was to never lose ground.

Following the battle of Teruel, the Nationalists, rather than reorganizing, regardless of the great losses suffered, decided to continue the action and take advantage of the momentum; after only a two-week break, they launched the battle of Aragon, nicknamed the March to the Sea, on March 9, aiming this time to split apart the Republican-held area and isolate the central and western regions from Catalonia in the northeast. The Nationalist offensive opened with massive artillery and aviation support, and by April 15 they had captured the seaside town of Vinaroz on the Mediterranean coast, thus establishing a corridor that effectively separated Catalonia from the rest of the Republican area and cut the Republic in two. It was here where tanks were employed at their best by the Nationalists and where the principles of mobile warfare were validated, even if in a limited way.

For the Republic, it was once more a complete disaster, of similar consequences to the